Simultaneous Tx/Rx Capability indication for multi-link operation 12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 Simultaneous Tx/Rx Capability indication for multi-link operation Date: 2019-09 Authors: Name Affiliations Address Phone email Yifan Zhou Huawei Bantian, Shenzhen, China    zhouyifan8@huawei.com  Jason Yuchen Guo Huawei   Yunbo Li  Huawei Ming Gan Yifan Zhou et al (Huawei) John Doe, Some Company

Introduction Multi-link operation is one of the features in 11be. 12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 Introduction Multi-link operation is one of the features in 11be. Which link to choose for transmission depends on the capabilities of involved links. Link capability (i.e. simultaneous Tx/Rx) should be announced before link selection and data transmission. Yifan Zhou et al (Huawei) John Doe, Some Company

12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 Multi-link operation Suppose link 1 and link 2 are selected for link aggregation between the AP and the STA. If two links are far apart and support simultaneous Tx/Rx, then both AP and STA can freely choose link 1 and/or link 2 for data transmission. Link 1 STA Device AP Device Link 2 Yifan Zhou et al (Huawei) John Doe, Some Company

12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 Multi-link operation Suppose the two links are too close to each other, and the STA don’t support simultaneous Tx/Rx due to interference mitigation. Therefore, when the STA is transmitting to the AP on link 1, the AP shall not transmit to the STA on link 2. AP Device Link 1 STA Device Link 2 Yifan Zhou et al (Huawei) John Doe, Some Company

Simultaneous Tx/Rx Capability Indication Sep. 2019 Simultaneous Tx/Rx Capability Indication Comparing these two scenarios, the STA and AP in the multi-link operation should take different actions, given different simultaneous Tx/Rx capabilities. Therefore, to make better link selection in multi-link operation, the simultaneous Tx/Rx capability of both STAs should be announced. Yifan Zhou et al (Huawei)

How to indicate – 1st method 12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 How to indicate – 1st method One bit to indicate simultaneous operation of each link pair, i.e., link 1 and link 2 1 means link 1 and link 2 support simultaneous Tx/Rx 0 means link 1 and link 2 don’t support simultaneous Tx/Rx Pairwise indication bits can be carried in the existing multi-band elements or neighbor report elements separately. For N links, N*(N-1)/2 bits are needed to indicate for all link pairs. Yifan Zhou et al (Huawei) John Doe, Some Company

Indicate in multi-band element 12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 Indicate in multi-band element In multi-band element, the band ID, operating class and channel number specify the channel frequency for which the multi-band element applies. The indication bits can be filled into the reserved subfields in multi-band control field or multi-band connection capability field. 1 indicates that the simultaneous Tx/Rx of the transmitting channel and the element-specified channel is supported by the transmitter, otherwise not. Yifan Zhou et al (Huawei) John Doe, Some Company

How to indicate – 2nd method 12/2/2019 doc.: IEEE 802.11-yy/xxxxr0 Sep. 2019 How to indicate – 2nd method Another method is that based on a predefined frequency gap threshold provided by the transmitter to the receiver. If two links are not closer than this threshold, then the receiver assumes that the transmitter support simultaneous Tx/Rx on these two links, otherwise not. Those thresholds can be delivered in the new EHT Capabilities element. Yifan Zhou et al (Huawei) John Doe, Some Company

Frequency gap between links Sep. 2019 Frequency gap between links Definition: gap between central working frequencies of two links. There are several options to determine the frequency gap threshold Transmitter-specific: each transmitter determine its own threshold BSS specific: an AP determines the threshold adopted within the BSS commonly defined: the Spec unifies a common and reasonable threshold for all devices. Yifan Zhou et al (Huawei)

09/2019 Conclusion Link capabilities should be announced before link selection and data transmission. In this proposal, two methods are provided to indicate the simultaneous Tx/Rx capabilities of link pairs for AP/STA devices. Yifan Zhou et al (Huawei)